Emigration is an aspect of human migration is the act of leaving one's country or region to settle in another. It is the same as immigration but from the perspective of the country of origin. Human movement in general is termed migration. There are many reasons why people might choose to emigrate. Some are for reasons of religious, political or economic freedom or escape. Others have personal reasons such as marriage. Some people living in rich nations with cold climates choose to move to warmer climates when they retire.

Some countries restrict the ability of their citizens to emigrate to other countries. After 1668, the Qing Emperor banned Han Chinese migration to Manchuria. In 1681, the emperor ordered construction of the Willow Palisade, a barrier beyond which the Chinese were prohibited from encroaching on Manchu and Mongol lands.[1]

At the end of World War II in 1945, the Soviet Union occupied several Eastern European countries, together called the Eastern Bloc, with the majority of those living in the newly acquired areas aspiring to independence and wanted the Soviets to leave.[4] Before 1950, over 15 million immigrants emigrated from Soviet-occupied eastern European countries to the west in the five years immediately following World War II.[5] By the early 1950s, the Soviet approach to controlling national movement was emulated by most of the rest of the Eastern Bloc.[6] Restrictions implemented in the Eastern Bloc stopped most East-West migration, with only 13.3 million migrations westward between 1950 and 1990.[7] However, hundreds of thousands of East Germans annually emigrated to West Germany through a "loophole" in the system that existed between East and West Berlin, where the four occupying World War II powers governed movement.[8] The emigration resulted in massive "brain drain" from East Germany to West Germany of younger educated professionals, such that nearly 20% of East Germany's population had migrated to West Germany by 1961.[9] In 1961, East Germany erected a barbed-wire barrier that would eventually be expanded through construction into the Berlin Wall, effectively closing the loophole.[10] In 1989, the Berlin Wall fell, followed by the unification of Germany and the dissolution of the Soviet Union.

Mynz, Rainer (1995), Where Did They All Come From? Typology and Geography of European Mass Migration In the Twentieth Century; EUROPEAN POPULATION CONFERENCE CONGRESS EUROPEAN DE DEMOGRAPHE, United Nations Population Division